Nergal’s mythological connection with death appears in the astrological reports, where there are numerous references to Mars precipitating widespread disease or carnage. In addition, like his brother Ninurta, Nergal appears in mythology as a war god, lord of battle. There is no doubt that this attribute was also attached to his planet, for in the reports there are many references to Mars causing an invasion of enemy troops, for example, “When a planet and Mars stand facing one another, there will be an invasion of the enemy.”
Michael Bageant, Astrology in Ancient Mesopotamia (free for 1 month at Scribd.com)